Archive for November, 2009

I sometimes feel bad about this, but I’m going to let a map I just received today jump to the front of the queue, as it was in the right place at the right time. This one comes from my colleague Tim Wallace, who was sitting next to me filling out a health insurance form.

It may surprise those of you who are not from the area to learn that Dane County, Wisconsin, does not look very much like that. The rigid lines of the Public Land Survey System, combined with the Wisconsin River, have left us with something that looks more like this:

Taken from Wikipedia article on Dane County.

Now, that being said, the fact that this map has a very high level of generalization is not inherently problematic. There are lots of very generalized, even cartoonish maps out there. It depends on the purpose and audience of your map, and sometimes fine details are not important. But I think they significantly overdid it here. It looks rather comic, and this clashes with the professional application (a healthcare provider directory) to which it’s being put. It seems haphazard and only loosely related to reality, and that makes me doubt the rest of the information that goes in to it.

The real lesson from today’s map, which applies to a lot of maps out there, is that it should not have been made. It conveys no useful spatial information. I can’t use it to figure out how to get to any of the UW clinics, and while I can sort of tell where clinics are in relation to each other (the heavy generalization makes that an estimate at best), that’s not really useful information unless you choose your health clinic based on its proximity to other clinics or cities. “I’m sorry, the village of McFarland has asked that I stay at least 10 miles away at all times, so I’ll need a clinic an appropriate distance away.” So, barring bizarre circumstances, I cannot tell how having a map is better than having a table of clinic locations. A table would, in fact, be significantly more useful, because you could use the clinic address to actually figure out how to get there. Not everything that has a location needs to be mapped, or can be usefully mapped.

Also, if you compare the two maps above, you will notice that the city dots for the clinic map don’t really bear a lot of resemblance to where those communities actually are in Dane county. And, in case you’re wondering, I spot checked this against the addresses for the clinics in Belleville and Verona, and it still did not match. The dots have only the loosest connection to reality. If geography really means so little here, why make a map? Again, a table would be better. The only reason the author of today’s map can get away with this level of generalization and haphazard dot placement is because the map is scarcely conveying any geographic information.

The labeling could be better, though it’s not horrible. It needs more consistency in how far the label is positioned relative to the dot. Look at Cross Plains vs. Waunakee. Why not put them both directly under the dot center, if that’s what you’re going for? And this is not to mention the lack of corner positions. It is conventional, and, as I have often been taught, rather easier to read, if you put the label in a corner position — that is, up and to the right of the dot, or down and to the left, etc. Fitchburg is also ambiguously placed — the label is about the same distance from two different dots. Would have been just fine if it were off to the left of the dot. Now, to be fair, not all labeling can be ideal, because geographic realities get in the way. But, the author of this map does not appear to have been strongly tied to geographic reality anyway, so I’m not sure if that’s an excuse in this case.

This map does not need a legend. A good map title should tell you what the map is about; since this map is about only one thing, if it’s well-titled I should be able to figure out what the red dots mean. If I’m looking at a map that’s titled “2009 UW Health Clinic Locations,” I’m not going to mistake those red dots for bowling alleys. Or cheese factories. Also, the dot in the legend is not only larger than the dots on the map, but a different shape. The ones on the map are more elliptical.

I was a little confused about the statement in the legend that says the communities of Black Earth and Cambridge are excluded — both are in Dane county. Skimming the report a bit, I think it’s because they’re not part of the UW Health Network. In which case, of course they wouldn’t be on the map — why would they bother to mention that? Chicago is also not included on this map, but they forgot to mention that one. On the other hand, if they are in the network, I have no idea why they would be left off. Maybe the author is no longer allowed to make maps of Black Earth.

In the end, this looks to me to be a classic case of “a table is too boring, let’s make a map!” But a table would have been a lot more useful for people who actually want to find a doctor.

One Nice Thing: The author set the county label in a different type than the city labels, strongly distinguishing them from each other.